1 Introduction ................................................ 1
1.1 Dual-polarization operational weather radars ............ 3
1.2 Fully polarimetric weather radars ....................... 5
2 Fundamentals of Radar Polarimetry ............................ 8
2.1 Wave Polarimetry: Jones vector .......................... 9
2.2 Wave Polarimetry: Wave Covariance matrix ............... 11
2.3 Target Polarimetry: Scattering matrix .................. 13
2.4 Target Polarimetry: Kennaugh matrix .................... 15
2.5 Target Polarimetry: Covariance (coherency) ............. 19
2.6 Target Decomposition Theorems .......................... 22
2.7 Problems in theoretical polarimetry .................... 25
2.8 Spinorial Concepts ..................................... 28
3 Polarimetric Weather Radar .................................. 36
3.1 Poldirad Architecture .................................. 38
3.2 Construction of the Instantaneous Scattering Matrix
(ISM) .................................................. 43
3.3 Weather Radar Variables ................................ 47
3.3.1 Fully polarimetric measurements at
horizontal/vertical polarization ................ 47
3.3.2 LDR mode ........................................ 50
3.3.3 ZDR mode ........................................ 51
3.3.4 Weather radar variables at circular
polarization basis .............................. 52
3.4 Weather radar variables: phenomenology ................. 54
3.4.1 Copolar Correlation Coefficient ................. 57
3.4.2 Linear Depolarization Ratio ..................... 59
4 Theoretical Results ......................................... 61
4.1 Overview ............................................... 61
4.2 The Depolarization Response: Theory .................... 64
4.3 The Depolarization Response: Applications .............. 70
4.3.1 Anisotropic weather targets ..................... 70
4.3.2 Isotropic weather targets ....................... 73
4.4 Propagation effects .................................... 75
4.4.1 Degree of polarization-propagation effects ...... 75
4.4.2 Entropy - propagation effects ................... 76
5 Experimental Results ........................................ 79
5.1 Overview ............................................... 79
5.2 Case study 1: Convective event ......................... 79
5.3 Case study 2: Convective event ......................... 85
5.3.1 Observation of rain ............................. 85
5.3.2 Observation of isotropic weather targets
(frozen hydrometeors) ........................... 91
5.4 Case study 3: Stratiform event ......................... 93
6 Conclusions (Thesen) ........................................ 98
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